Cleveland Browns wide receiver Josh Gordon will miss the beginning of training camp due to his “overall health and treatment plan” that continues to help him work his way back from a series of off-field issues, Gordon tweeted Monday morning. He will be placed on the non-football illness reserve list.

Josh Gordon will not be in attendance for the opening of Browns training camp. (AP)

Gordon: ‘I am not only doing great physically but mentally as well’

Gordon, 27, has a long list of drug-related problems that have kept him off the field in the past. He missed all of the 2015 season due to a violation of the league substance-abuse policy. He also missed the 2016 season and has spent considerable time in rehab.

Though it has been a long road back, Gordon seems to be in a better place now, thanks to help from the league, rehabilitation and other resources. As he expresses in the latter half of his tweet above, his absence from training camp is not one that should signal panic:

With the help of the NFL, NFLPA, and the Browns’ organization, I have been able to utilize the resources available to me that will ensure my well-being on and off the field. By continuing to follow the plan set up by our medical director and his team and taking this time before this season starts, we believe it will help me maintain the progress I’ve made not only today but for many years to come.

Thank you all for your patience, love, and support! Go Browns!

ESPN’s Adam Schefter reported that the absence isn’t related to a relapse.

Browns’ WR Josh Gordon did not have any slip ups or failed tests, per sources. His leave is a pro-active, defensive gesture to get extra counseling to try to ensure he does not have any of the setbacks that have marked his past. Those who know him say he has “worked his a— off.”

We will continue to support Josh as he receives the care needed to maintain his progress. We are going to respect his privacy while he is away from the team. Josh will be placed on the non-football illness reserve list until he is ready to return.

On this list, Gordon can be activated at any time. He expects to be ready in plenty of time for the regular season.

NFL Network’s Tom Pelissero tweeted Gordon is “absolutely not suspended,” and NFL spokesman Brian McCarthy said the league will address the situation, “at the appropriate time.”

The Browns open training camp Thursday

Cleveland opens training camp in Berea, Ohio on Thursday. Though it is not immediately apparent how long Gordon will be absent, he will not be there for the start due to his ongoing recovery.

It’s a big season for Gordon, first and foremost to prove that he can stay on the field, but also to develop chemistry with new quarterbacks Tyrod Taylor and Baker Mayfield. The Browns are also being filmed for “Hard Knocks,” and Gordon will almost certainly be a key character in that.